Drum shaped vessel assembly

ABSTRACT

A drum shaped vessel assembly suitable for use in an absorption refrigerator comprises two elongated vessels which when assembled provide a circular cross-sectional configuration and joints disposed in the air gap defined between confronting inner surfaces of the vessels, said joints rigidly interconnecting the vessels in a direction perpendicular to the inner surfaces of the vessels but permitting relative movement thereof in the longitudinal direction.

United States Patent Iwasawa et al.

[ 51 May2, 1972 [54] DRUM SHAPED VESSEL ASSEMBLY [72] inventors: SeiJlro 1wasawa, Yokohama; Masabumi lshlmura, Kokubunji; Kenshichiro Morishita, Yokohama, all of Japan [73] Assignee: Tokyo Shibaura Denki Kabushiki Kaisha, (a/k/a Tokyo Shibaura Electric Co., Ltd.), Kawasaki-shi, Japan [22] Filed: Feb. 18, 1971 21 Appl. No.: 116,577

[30] Foreign Application Priority Data Feb. 27, 1970 Japan ..45/l6846 U.S. Cl. ..62/476, 165/67, 165/81 ..F25b 15/04, F28f 7/00 Field of Search ..62/476, 302; 165/67, 78, 81,

[56] References Cited UNITED STATES PATENTS 1,539,267 5/1925 Muhleisen ..165/82 X 2,084,324 6/1937 Dewald ..l65/78 3,236,295 2/1966 Yurko ..l65/67 3,398,787 8/1968 Bevevino.... ..165/8l 3,605,879 9/1971 Schaefier ..165/82 X Primary Examiner-William F. ODea Assistant Examiner-P. D. Ferguson Attorney-Robert E. Burns and Emmanuel J. Lobato ABSTRACT A drum shaped vessel assembly suitable for use in an absorption refrigerator comprises two elongated vessels which when assembled provide a circular cross-sectional configuration and joints disposed in the air gap defined between confronting inner surfaces of the vessels, said joints rigidly interconnecting the vessels in a direction perpendicular to the inner surfaces of the vessels but pennitting relative movement thereof in the longitudinal direction.

4 Claims, 7 Drawing Figures PATENTEUMM 2|972 3,659,431 sum 10F 2 PATENTEDMAY 2 I972 SHEET 2 BF 2 FIG. 6 PRIOR ART FIG. 7PR|0R ART DRUM SHAPED VESSEL ASSEMBLY BACKGROUND OF THE INVENTION This invention relates to a drum shaped vessel device or assembly comprising a high pressure, high temperature vessel and a low pressure, low temperature vessel which are assembled to form a single drum suitable for use in absorption type refrigrators and the like applications requiring independent chambers or vessels operating under different conditions.

Although not limited to a particular application, for the sake of description, the background of the invention will be described in terms of an absorption refrigerator for industrial use. With reference first to FIG. 7 of the accompanying drawing, a single drum type absorption refrigerator generally comprises an evaporator 1, an absorber 2, a generator 3, and a condenser 4 which are contained in a single drum 10. Outside the drum are disposed a heat exchanger and a circulation pump 6. The interior of the drum is divided by'a horizontal barrier 50 including one or more expansion tubes 7 into a high pressure chamber 8 containing evaporator 1 and absorber 2, and a low pressure chamber 9 containing generator or boiler 3 and condenser 4. Since the construction and operation of such an absorption refrigerator are well known in the art only essential component parts and their relative arrangement are illustrated diagrammatically in FIG. 7.

Such absorption type refrigerators are used for the air conditoning of buildings or factory processing systems. In operation, water or other medium to be cooled is circulated through evaporator 1 and cooling water is circulated through absorber 2 and condenser 4. Heating medium such as steam or combustion gas acting as the energy source of the refrigerator is circulated through generator 3.

In operation, in evaporator l, the refrigerant evaporates at a low temperature (about 5 C., in an absorption refrigerator utilizing lithium bromide LiBr as the absorbent and water as the refrigerant) and under a low pressure (about 6 mm Hg when utilizing the same absorbent and refrigerant). Where a liquid absorbent (aqueous solution of lithium bromide, for example) maintained at a constant low temperature is used, it is possible to maintain the evaporator l at the low pressure and the vapor of the refrigerant generated in evaporator 1 is absorbed by the liquid absorbent in absorber 2.

For this purpose, evaporator l and absorber 2 are communicated through a relatively large opening and the liquid absorbent in absorber 2 that has been diluted by absorbing the vapor of the refrigerant is sent to generator 3 by means of the pump 6 and is heated by the heating medium circulated through the generator to generate the vapor of the refrigerant at an elevated temperature (about 100 C. in the above example) and under a pressure higher than in the evaporator (however this pressure is much lower than the atmospheric pressure and is about 70 mm Hg in the absorption refrigerator described above, which is rather close to vacuum). The vapor of the refrigerant generated in generator 3 flows into condenser 4 through a relatively wide opening and is condensed by the cooling water circulating through the condenser which maintaines the desired pressure in generator 3. The liquid refrigerant condensed by condenser 4 is supplied to evaporator 1 through expansion tubes 7.

Heat exchanger 5 absorbs heat from the relatively high temperature liquid absorbent returned from generator 3 to absorber 2 and gives the absorbed heat to the relatively low temperature liquid absorbent sent to generator 3 from absorber 2 thus improving heat effeciency.

Thus, it will be apparent that the illustrated absorption refrigerator must be provided with relatively low pressure and low temperature chamber 8 containing evaporator 1 and absorber 2 and a relatively high pressure (actually, however, a pressure lower than the atmospheric pressure and close to the vacuum) and high temperature chamber 9 containing generator 3 and condenser 4.

Heretofore, these low pressure, low temperature chamber 8 and high pressure, high temperature chamber 9 have been formed in a single drum 10 as shown in FIGS. 5 and 7 or as independent drums l1 and 12 as shown in FIG. 6. The former type is termed as the single drum type whereas the latter type as the twin drum type. With the single drum type, as a portion of the refrigerant in evaporator l evaporates in vain due to the heat transferred to low temperature, low pressure chamber 8 from high temperature, high pressure chamber 9 due to close disposition of these chambers, thereby decreasing the heat effeciency of the refrigerator. To decrease heat transmission it is necessary to interpose a heat inslator layer or a vacuum chamber between the high and low pressure chambers 9 and 8 or to use a double walled partition therebetween.

Moreover, since the high temperature, high pressure chamber 9 and the low temperature, low pressure chamber 8 are contained in the same drum 10, heat stresses due to the difference in the thermal expansion will occur at the interface between these chambers and at the joints between headers and bundles of tubes comprising evaporator l, absorber 2, generator 3 and condenser 4. Disposition of a number of component elements in a drum of limited volume also complicates the construction and makes diflicult them to assembly. Further, as it is necessary to assemble these component parts in the factory and then transport and install the completed drum at the field, the capacity or the diameter of the drum is limited.

On the other hand, while the twin drum type is advantageous in that it is more easy to transport and install, as two drums are superposed one upon the other as shown in FIG. 6, the total height of the assembly becomes high which is objectional where the assembly is to be installed in the basement of a building.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a novel drum shaped vessel assembly which has advantages of both single drum type and twin drum type, that is an assembly having substantially the same overall height as the single drum type, is easy to transport and install and can prevent transmission of heat between high and low temperature chambers and heat stress due to the difference in the thermal expansion.

More specific object of this invention is to provide a novel drum shaped vessel assembly especially suitable for use in absorption type refrigerators.

Another object of this invention is to join or assemble a high temperature vessel and a low temperature vessel such that the cross-sectional cinfiguration of the assembly resembles that of a single drum, that the high temperature and low temperature vessels are spaced apart to effectively prevent heat transfer therebetween and that these vessels can be moved relatively in the longitudinal direction so as to prevent undue stress or rupture due to the difference in the thermal expansion.

According to this invention there is provided a drum shaped vessel assembly comprising a plurality of elongated vessels operating at difierent temperatures, the vessels having confronting inner surfaces which are spaced apart to define an air gap therebetween, and arcuate outer surfaces, the outer surfaces defining a circle when the plurality of vessels are assembled, and a plurality of joints disposed in the air gap, the joints rigidly interconnecting the vessels in a direction substantially perpendicular to the inner surfaces but permitting the vessels to move relatively in the longitudinal direction.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing:

FIG. 1 is a perspective view of a drum shaped vessel assembly embodying this invention and designed to act as an absorption type refrigerator;

FIG. 2 is a partial view to illustrate modified joints;

FIG. 3 is a side elevation of the joints shown in FIG. 2 as seen in the direction of arrow III;

FIG. 4 is an end elevation of a modified vessel assembly of this invention;

FIG. 5 shows a diagrammatic perspective view of a prior art single drum type absorption refrigerator;

FIG. 6 shows a diagrammation perspective view of a prior art twin drum type absorption refrigerator; and

FIG. 7 shows a transverse section of a prior art single drum type absorption refrigerator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now to FIG. 1 of the accompanying drawings, the novel drum shaped vessel assembly comprises two elongated pressure tight vessels A and B having arcuate peripheries and confronting fiat horizontal inner surfaces 13 and 14 which are coupled together by means of novel joints C such that the cross-sectional configuration of the assembly resembles that of a single circular drum.

Each joint extends in the longitudinal direction of the assembly and comprises an inverted T shaped member 17 with its leg secured to the surface 14 of vessel B and a channel shaped member 16 receiving the head of member 17, said channel shaped member 16 having a leg secured to surface 13 of vessel A. When coupled together with these joints, vessels A and B cannot move relatively in the vertical direction but are free to move relatively in the horizontal direction.

In the illustrated example, vessel A comprises low pressure chamber 8 containing evaporator 1 and absorber 2 whereas vessel B high pressure chamber 9 containing generator 3 and condenser 4.

FIGS. 2 and 3 show modified joints C consisting of a plurality of pairs of bearing members 18 which are arranged in a plurality of longitudinal rows. Each pair of joints includes two oppositely directed bearing members 18 each having a tubular section and a vertical leg. A horizontal shaft 19 is slidably fitted in the tubular sections of aligned bearing members in each row. The legs of each pair of bearing members 18 are rigidly connected to surfaces 13 and 14 of vessels A and B respectively. With this construction, although vessels A and B are connected rigidly in the vertical direction but are free to move relatively in the horizontal direction.

In a modified embodiment shown in FIG. 4, opposing surfaces 13 and 14 of vessels A and B have more complicated configurations. Thus, these surfaces comprise horizontal sections 13a and 14a, vertical sections 13b and 14b and inclined sections 13c and 140, respectively, which are confronting each other to define an air gap D therebetween. The joints C used to interconnect vessels A and B may be of the same type as those shown in FIG. 1.

Air gap D defined between confronting surfaces 13 and 14 of vessels A and B in each embodiment is effective to provide heat insulation between two vessels operating at different temperatures and under different pressures thus eliminating the provision of a heat insulator or a vacuum chamber between two vessels.

Since joints C rigidly interconnect two vessels A and B in the vertical direction, they act to balance the force acting on the surface 13 of vessel A due to the difference between internal and external pressures against the force acting on surface 14 of vessel 14 due to the difference between internal and extemal pressures thus preventing excessively large bending moments from being applied upon surfaces 13 and 14.

Where vessel A acts as a low pressure, low temperature chamber and vessel B as a high pressure, high temperature chamber, the novel joints C permit relative movement of vessels A and B in the horizontal direction due to the difference in the thermal expansion, thus eliminating undesirable stress which otherwise would be caused where vessels A and B cannot move relatively in the horizontal direction.

Thus, it will be clear that this invention provides a novel drum shaped vessel assembly having substantially equal crosssectional configuration as the single drum type so that the overall height can be reduced when compared with the twin drum type. Further, as two vessels are assembled independently, their fabrication, transportation and installation in the field are more easy than the single drum type. The arr gap defined between confronting surfaces of two vessels prevents heat transfer between two vessels operating at different temperatures without the necessity of using any heat insulator or vacuum chamber. Moreover, the novel joints permit relative longitudinal movement of two vessels.

What is claimed is:

1. A drum shaped vessel assembly comprising a plurality of elongated vessels operating at different temperatures, said vessels having confronting inner surfaces which are spaced apart to define an air gap therebetween, and arcuate outer surfaces, said outer surfaces defining a circle when said plurality of vessels'are assembled, and a plurality of joints disposed in said air gap, said joints rigidly interconnecting said vessels in a direction substantially perpendicular to said inner surfaces but permitting said vessels to move relatively in the longitudinal direction thereof.

2. The drum shaped vessel assembly as claimed in claim 1 wherein each of said joints comprises an inverted T shaped member having its leg secured to the inner surface of one vessel and a channel shaped member slidably receiving the head of said Tshaped membeer, said channel shaped member being secured to the inner surface of another vessel.

3. The drum shaped vessel assembly as claimed in claim 1 wherein said joints are provided in a plurality of rows in the longitudinal direction of said vessels, and each row comprises a longitudinal shaft and a plurality of pairs of bearing members, each pair of bearing members having tubular sections slidably receiving said shaft and legs secured to said confronting inner surfaces of said vessels.

4. A drum shaped vessel assembly for use in an absorption refrigerator, comprising a pair of elongated sealed vessels, one of said vessels containing an evaporator and an absorber whereas the other vessel containing a generator and a condenser, said vessels having confronting inner surfaces which are spaced apart to define an air gap therebetween and arcuate outer surfaces, said outer surfaces defining a circle when said pair of vessels are assembled, and a plurality of joints disposed in said air gap, said joints rigidly interconnecting said vessels in a direction substantially perpendicular to said inner surfaces but permitting said vessels to move relatively in the longitudinal direction thereof. 

1. A drum shaped vessel assembly comprising a plurality of elongated vessels operating at different temperatures, said vessels having confronting inner surfaces which are spaced apart to define an air gap therebetween, and arcuate outer surfaces, said outer surfaces defining a circle when said plurality of vessels are assembled, and a plurality of joints disposed in said air gap, said joints rigidly interconnecting said vessels in a direction substantially perpendicular to said inner surfaces but permitting said vessels to move relatively in the longitudinal direction thereof.
 2. The drum shaped vessel assembly as claimed in claim 1 wherein each of said joints comprises an inverted T shaped member having its leg secured to the inner surface of one vessel and a channel shaped member slidably receiving the head of said T-shaped membeer, said channel shaped member being secured to the inner surface of another vessel.
 3. The drum shaped vessel assembly as claimed in claim 1 wherein said joints are provided in a plurality of rows in the longitudinal direction of said vessels, and each row comprises a longitudinal shaft and a plurality of pairs of bearing members, each pair of bearing members having tubular sections slidably receiving said shaft and legs secured to said confronting inner surfaces of said vessels.
 4. A drum shaped vessel assembly for use in an absorption refrigerator, comprising a pair of elongated sealed vessels, one of said vessels containing an evaporator and an absorber whereas the other vessel containing a generator and a condenser, said vessels having confronting inner surfaces which are spaced apart to define an air gap therebetween and arcuate outer surfaces, said outer surfaces defining a circle when said pair of vessels are assembled, and a plurality of joints disposed in said air gap, said joints rigidly interconnecting said vessels in a direction substantially perpendicular to said inner surfaces but permitting said vessels to move relatively in the longitudinal direction thereof. 